A keyboard-type percussion instrument capable of outputting, with high quality, a musical tone to outside the instrument. In an upper part of the instrument, there is provided a tone generator unit including sounding members disposed to respectively correspond to keys of a keyboard and a resonance box in which musical tones generated by sounding members resonate. Action mechanisms each having a hammer felt for striking a corresponding sounding member are disposed below the tone generator unit. Reflection plates and a keybed formed with tone output ports are disposed below the action mechanisms. A musical tone generated by a sounding member struck by a corresponding hammer felt resonates in the resonance box, is output therefrom, passes through the tone output ports, is reflected by the reflection plates, and is output toward rearward of the instrument.